A stress test is used to help diagnose and evaluate heart problems such as ischemic heart disease, heart valve disease, or heart failure. Your doctor may recommend this test if you have symptoms of a heart problem, such as shortness of breath, chest pain, dizziness, and a rapid or irregular heartbeat. If your doctor does find a problem, the stress test also can help your doctor choose the right treatment plan and determine what types of physical activity are safe for you.
A stress test usually involves physical exercise such as walking on a treadmill or riding a stationary bicycle. The test may be done in a hospital or doctor’s office. As you exercise, your doctor will measure your heart rate and blood pressure and your heart’s electrical activity. If you are not able to exercise, your doctor will give you medicine that will make your heart work hard and beat faster, as if you were exercising.
Your doctor will carefully monitor you throughout the test to minimize the risk of complications caused by the exercise or medicine used to raise your heart rate. Intense exercise during the test can cause some heart problems to get worse. If your doctor gives you medicine to make your heart beat harder instead of having you exercise, there is a small risk of developing certain heart problems after the test.
What To Expect
A stress test is usually done in a hospital or doctor’s office. Your doctor will give you instructions to prepare for the test and tell you what to expect during and after the test.
Stress test. The image shows a patient having an exercise stress test. Electrodes are attached to the patient’s chest and connected to an electrocardiogram (EKG) machine. The EKG records the heart’s electrical activity. A blood pressure cuff records the patient’s blood pressure while he walks on a treadmill.
Before the stress test:
Your doctor may ask you not to take some of your prescription medicines or to avoid coffee, tea, or any drinks with caffeine on the day of your test, because these may affect your results. Your doctor will ask you to wear comfortable clothes and shoes for the test.
For the stress test, your doctor will put sticky patches called electrodes on your chest and attach a blood pressure cuff to your arm and a pulse monitor to your finger or other part of your body. Your doctor will measure your heart activity and blood pressure before you start the test.
During the stress test:
You will slowly start to exercise on a treadmill or stationary bicycle, and then gradually increase the treadmill speed or bicycle resistance until your heart is working at the target heart rate for your age. Most often, a stress test includes an electrocardiogram to measure your heart’s electrical activity as you exercise on a treadmill or on a stationary bicycle. Your doctor may also measure your blood oxygen level, blood pressure, and heart rate. During the test, you will exercise for 10 to 15 minutes. Your doctor will stop the test if you show any sign of a heart problem, or if you are too tired to continue the test.
If you are not able to exercise, your doctor will give you medicine over a 10- to 20-minute period through an intravenous (IV) line into one of your blood vessels.
Your doctor may also take images of your heart during or right after the stress test to see how well blood is flowing through your heart and how well your heart pumps blood when it beats. These pictures can be taken by echocardiography or by injecting a radioactive dye into one of your veins, called a nuclear heart scan. The amount of radiation in the dye is considered safe for you and those around you. However, if you are pregnant, you should not have this test because of risks it might pose to your unborn child.
If your doctor also wants to see how well your lungs are working, you may be asked to wear a mask or mouthpiece to measure the gases that you breathe out during the stress test.
After the stress test:
After the stress test, your doctor will measure your heart activity and blood pressure to make sure that both measurements are back within the normal range. You should be able to return to your normal activities right away. If you had a test that involved radioactive dye, your doctor may ask you to drink plenty of fluids to flush it out of your body.
If your stress test shows that your heart is healthy, you may not need further testing or treatment. Your doctor may order other diagnostic tests or imaging tests if the stress test results suggest that you may have a heart condition, if you are physically unable to exercise, or if you continue having symptoms, such as shortness of breath or chest pain.